Case 1 was a 43-year-old woman, who was diagnosed as having PBC. After one month, she was hospitalized owing to sudden temporary unconsciousness. She was diagnosed as having acute lymphoid leukemia (ALL) by bone marrow examination. Chemotherapy was done, but she died after 6 months. Case 2 was a 54-year-old woman, who was diagnosed as having PBC with CREST syndrome. Seven years later, she was diagnosed as having acute promyelocytic leukemia (APL) by bone marrow examination. Chemotherapy was continued, and her symptoms are at present, stable. To date, there have been no reports of PBC complicated by acute leukemia.